动态显示textarea中输入的字数
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><head><meta http-equiv="Content-Type" content="text/html; charset=gb2312" /><meta name="robots" content="all" /><meta name="keywords" content="JS,Blog,ASP,designing,with,web,standards,xhtml,css,graphic,design,layout,usability,accessibility,w3c,w3,w3cn" /><meta name="descrīption" content="JS限制textarea输入框输入字数" /><title>JS限制textarea输入框输入字数</title><script type="text/javascript">function checktext(text){ allValid = true; for (i = 0; i < text.length; i++) { if (text.charAt(i) != " ") { allValid = false; break; } }return allValid;}function xx(message,total,used,remain){ var max; max = total.value; if (message.value.length > max) { message.value = message.value.substring(0,max); used.value = max; remain.value = 0; alert("留言不能超过 200 个字!"); } else { used.value = message.value.length; remain.value = max - used.value; }}</script><style type="text/css"><!--* {padding:0; margin:0;}body, html {text-align:left; font-size:12px; line-height:150%; margin:0 auto; background:#fff; padding-top:20px;}fieldset {padding:10px; width:550px; margin:0 auto;}legend {font-size:14px; font-weight:bold;}.inputtext {border:none; background:#fff;}--></style></head><body><form action="SaveData.asp" method="post" onSubmit="return datacheck();"><fieldset><legend>请输入内容</legend><textarea name="Memo" rows="10" wrap=PHYSICAL cols="75" onKeyDown="xx(this.form.Memo,this.form.total,this.form.used,this.form.remain);" onKeyUp="xx(this.form.Memo,this.form.total,this.form.used,this.form.remain);"></textarea><p>最多字数：<input disabled maxLength="4" name="total" size="3" value="200" name="used" size="3" value="0" name="remain" size="3" value="200" class="inputtext"></td></p></fieldset></form></body></html>